#define _CRT_SECURE_NO_WARNINGS  1

#include"Stack.h"

void STInit(ST* ps)
{
	ps->a = (STDataType*)malloc(sizeof(STDataType) * 4);
	ps->capacity = 4;
	ps->top = 0;
}

void STDestroy(ST* ps)
{
	free(ps->a);
	ps->a = NULL;
	ps->capacity = 0;
	ps->top = 0;
}

void STPush(ST* ps, STDataType x)
{
	if (ps->capacity == ps->top)
	{
		STDataType* tmp = (STDataType*)realloc(ps->a, sizeof(STDataType)*(ps->capacity) * 2);
		ps->a = tmp;
		ps->capacity *= 2;
	}
	ps->a[ps->top] = x;
	ps->top++;
}

void STPop(ST* ps)
{
	ps->top--;
}

int STSize(ST* ps)
{
	return ps->top;
}

bool STEmpty(ST* ps)
{
	return ps->top == 0;
}

STDataType STTop(ST* ps)
{
	return ps->a[ps->top-1];
}